View source for Apical membrane

The 'apical membrane' is a term coined in biology to describe the membrane&nbsp;exposed to&nbsp;the [[lumen]]&nbsp;of an [[organ|organ]]&nbsp;for example, the lumen of the [[small intestine|small intestine]]&nbsp;or an external environment. It is the opposing membrane of the [[basal|basal]] or [[basolateral membrane|basolateral membrane]].